Fixture material advice needed.

[scottp55]

I've been using the OSB pallet skids that came with MakerCrate that I didn't use.
With 5 layers of lacquer on them to minimize carpet tape(2" Ace Hardware heavy duty fiberglass) removal problems/humidity/temp changes. They worked fine for prototypes, but now need production type material for Northern Desktop.
Material needs to be VERY stable, .75" thick, capable of thousands of clamp/releases, abrasion resistant, carpet tape needs to stick to it well, but release with little or no residue. Will also be have the 1/4" stock on top "whacked" numerous times a day with a dead blow hammer(using Butternut scrap to prevent marring).
Originally looked at Corian but need 3/4", Then looked at HDPE and reprocessed black UHMW.
http://www.eplastics.com/HDPE_Sheet
https://www.interstateplastics.com/Uhmw-Black-Reprocessed-Sheet-UHMBR.php?sku=UHMBR&vid=201501131108-3p&dim2=8&dim3=24&thickness=0.750&qty=1&recalculate.x=31&recalculate.y=17

I know Nothing about plastics though, and we'll need 6, about .75X8X24" and don't want to break the bank OR through ignorance buy something that doesn't work:(
Another consideration is that once we find out what size and design sells best, we will be using this material for job specific vacuum jigs using AllStar Adhesives cover gasket.
Are there other materials I should be looking at?
ANY advice will be very welcome as I need to jump on this soonest.
Thanks,
scott

[maverickx50]

Might try Phenolic. We used to use it a lot for easy to Mfg. jigs & fixtures in the metalworking industries. Even available as a plywood coating. Here are two possible web sites to check out. Very stable, Good wear, machines much like a hard wood (Oak).


http://www.woodcraft.com/Product/131170/phenolic-faced-plywood-18mm34-x-24-x-48.aspx


https://www.interstateplastics.com/phenolic-sheets.php?searchtext=phenolic%20board&kw=phenolic%20board&gclid=COiP5M7UkcMCFdKEfgodOC0AsQ

[bleeth]

I second the solid phenolic, although UHMW may work for you since the pieces are fairly small. The latter can bend easier but is less brittle.

Tape residue will come off both easily with 3m adhesive cleaner available at big orange. It will wipe off in a heartbeat with pure acetone but test first as some plastic doesn't like acetone. MEK also takes off tape residue really fast without attacking plastic. Neither is fun to absorb though so wear rubber gloves when using.

[gundog]

I think the Phenolic would be better than UHMW or HDPE neither material will be stable if you have any heat and cooling they have a great deal of thermal expansion. The plastic may not stick well with the tape I am not sure. I can try it as I cut lots of the stuff. If you pay the shipping I can send you some scrap UHMW and HDPE to play with.

Mike

[scottp55]

Thanks Fredrick and Dave,
Only phenolic I've ever even touched is Buck handles,lignostone, and this routerplate (and NEVER CNC'd) from Woodworkers Warehouse(may they R.I.P.). Not TOTALLY sure this router table insert IS phenolic, but I seem to remember it is.

Any idea of which of the several phenolics it is?
I just use it to lap stone and wood with 4"PC adhesive sandpaper. If it's the same stuff then I can try some small sample cuts/solvent tests/carpet tape tests.
Does it need any special bits?
Can I tablesaw it? What blade works best? I have new Delta combo blade,New Freud Rip and Crosscut. (need to do homework:(
I was thinking of going .75X12X24" so I could do 3 4" Ocooch thin stock(.25") or 2 6" pieces at a time and use less blanks? BUT worried the Shopfox clamps will cause bowing? Is that a concern with this stuff(OR the plastics)?

Mike, thanks for the kind offer!!
Gladly pay shipping for scraps if you E-mail me (address in contact info). I only have company debit card for expenses though(MC). is that doable? Tight month for my personal cash due to heating season/global warming (5F heat wave today:)
Let me know.
Thanks again guys,
scott

[scottp55]

Oh, Don't think the phenolic surfaced ply would work as they each have to be as close to identical as possible(so probably have to dimension and resurface). Idea that seems to work for production is, Toolpath Zeroed to bottom of material, then zero 1 bit and run a blank-swap out, slide new blank in, RR, swap out etc. Then new bit zeroed and rinse/ repeat. So far(so long as I blow out sawdust) seems to be accurate enough to to drill buttonholes and even swapping out, the buttonholes countersink evenly.
Not sure if it's accurate enough for inlay or 3D buttons yet.

[adrianm]

I use a material called Tufnol Kite over here in the UK for all my jigs and fixtures.

[scottp55]

Adrian,
Are these two comparable?
It mentions not suitable for high humidity---NOT high humidity application, but humidity does vary as Kirk's Dads shop is coal stove heated and they've been 0 to -30F which is normal and only add humidity during the day(cast kettle on stove). Because file is run from bottom of material(spoilboard) it could affect cutout and button holes.
Does that throw out the paper phenolics? OR is it such a small amount (<.001")I shouldn't worry about?
Still reading.
Thanks,
scott
http://www.tufnol.com/materials-full/paper-laminates/kit-brand-standard-sizes.aspx
https://www.interstateplastics.com/Phenolic-Economy-Natural-Paper-masked-Sheet-PHENPE.php?sku=PHENPE&vid=201501140607-6p&dim2=12&dim3=24&thickness=0.750&qty=1&recalculate.x=25&recalculate.y=16

[scottp55]

Kirk, Only been to your shop once last January and you had the shop toasty for me.
Can you please post here shop temp/humidity first thing in the morning and say mid afternoon at this time of year. Also what are normal summer temp ranges in a day in shop?
Not important to your Dad as he's a Carver, but maybe give others an idea if it would preclude us from using a bottom referenced run file because of temp/humidity expansion:(

[bobmoore]

I would buy machined aluminum for best results and switch to vacuum hold down. Second choice would be to epoxy 2 layers of corian and have them machined to desired the thickness. Bob

[adrianm]

My shop varies in temp from 5 degrees C up to about 30 degrees C and I haven't had any issues with expansion with the tufnol.

Never measured the humidity but I think it would have to vary a lot. Especially with the amount of rain we're getting at the moment!

[gbradley]

Scott

For a cheep fixture you could go with HDPE. This link is for a 48" piece but you can find smaller on amazon and ebay

http://www.eplastics.com/HDPEBLK0-750SR24X48